import { BLUE, WHITE } from '../common/color'
import { VantComponent } from '../common/component'
import { getSystemInfoSync } from '../common/utils'
import { isObj } from '../common/validator'
import { canIUseCanvas2d } from '../common/version'
import { adaptor } from './canvas'
function format(rate) {
  return Math.min(Math.max(rate, 0), 100)
}
const PERIMETER = 2 * Math.PI
const BEGIN_ANGLE = -Math.PI / 2
const STEP = 1
VantComponent({
  props: {
    text: String,
    lineCap: {
      type: String,
      value: 'round',
    },
    value: {
      type: Number,
      value: 0,
      observer: 'reRender',
    },
    speed: {
      type: Number,
      value: 50,
    },
    size: {
      type: Number,
      value: 100,
      observer() {
        this.drawCircle(this.currentValue)
      },
    },
    fill: String,
    layerColor: {
      type: String,
      value: WHITE,
    },
    color: {
      type: null,
      value: BLUE,
      observer() {
        this.setHoverColor().then(() => {
          this.drawCircle(this.currentValue)
        })
      },
    },
    type: {
      type: String,
      value: '',
    },
    strokeWidth: {
      type: Number,
      value: 4,
    },
    clockwise: {
      type: Boolean,
      value: true,
    },
  },
  data: {
    hoverColor: BLUE,
  },
  methods: {
    getContext() {
      const { type, size } = this.data
      if (type === '' || !canIUseCanvas2d()) {
        const ctx = wx.createCanvasContext('van-circle', this)
        return Promise.resolve(ctx)
      }
      const dpr = getSystemInfoSync().pixelRatio
      return new Promise((resolve) => {
        wx.createSelectorQuery()
          .in(this)
          .select('#van-circle')
          .node()
          .exec((res) => {
            const canvas = res[0].node
            const ctx = canvas.getContext(type)
            if (!this.inited) {
              this.inited = true
              canvas.width = size * dpr
              canvas.height = size * dpr
              ctx.scale(dpr, dpr)
            }
            resolve(adaptor(ctx))
          })
      })
    },
    setHoverColor() {
      const { color, size } = this.data
      if (isObj(color)) {
        return this.getContext().then((context) => {
          if (!context) return
          const LinearColor = context.createLinearGradient(size, 0, 0, 0)
          Object.keys(color)
            .sort((a, b) => parseFloat(a) - parseFloat(b))
            .map((key) => LinearColor.addColorStop(parseFloat(key) / 100, color[key]))
          this.hoverColor = LinearColor
        })
      }
      this.hoverColor = color
      return Promise.resolve()
    },
    presetCanvas(context, strokeStyle, beginAngle, endAngle, fill) {
      const { strokeWidth, lineCap, clockwise, size } = this.data
      const position = size / 2
      const radius = position - strokeWidth / 2
      context.setStrokeStyle(strokeStyle)
      context.setLineWidth(strokeWidth)
      context.setLineCap(lineCap)
      context.beginPath()
      context.arc(position, position, radius, beginAngle, endAngle, !clockwise)
      context.stroke()
      if (fill) {
        context.setFillStyle(fill)
        context.fill()
      }
    },
    renderLayerCircle(context) {
      const { layerColor, fill } = this.data
      this.presetCanvas(context, layerColor, 0, PERIMETER, fill)
    },
    renderHoverCircle(context, formatValue) {
      const { clockwise } = this.data
      // 结束角度
      const progress = PERIMETER * (formatValue / 100)
      const endAngle = clockwise ? BEGIN_ANGLE + progress : 3 * Math.PI - (BEGIN_ANGLE + progress)
      this.presetCanvas(context, this.hoverColor, BEGIN_ANGLE, endAngle)
    },
    drawCircle(currentValue) {
      const { size } = this.data
      this.getContext().then((context) => {
        if (!context) return
        context.clearRect(0, 0, size, size)
        this.renderLayerCircle(context)
        const formatValue = format(currentValue)
        if (formatValue !== 0) {
          this.renderHoverCircle(context, formatValue)
        }
        context.draw()
      })
    },
    reRender() {
      // tofector 动画暂时没有想到好的解决方案
      const { value, speed } = this.data
      if (speed <= 0 || speed > 1000) {
        this.drawCircle(value)
        return
      }
      this.clearMockInterval()
      this.currentValue = this.currentValue || 0
      const run = () => {
        this.interval = setTimeout(() => {
          if (this.currentValue !== value) {
            if (Math.abs(this.currentValue - value) < STEP) {
              this.currentValue = value
            } else if (this.currentValue < value) {
              this.currentValue += STEP
            } else {
              this.currentValue -= STEP
            }
            this.drawCircle(this.currentValue)
            run()
          } else {
            this.clearMockInterval()
          }
        }, 1000 / speed)
      }
      run()
    },
    clearMockInterval() {
      if (this.interval) {
        clearTimeout(this.interval)
        this.interval = null
      }
    },
  },
  mounted() {
    this.currentValue = this.data.value
    this.setHoverColor().then(() => {
      this.drawCircle(this.currentValue)
    })
  },
  destroyed() {
    this.clearMockInterval()
  },
})
